:rolleyes: why do people living different reigons have different skin colours? :confused:

Skin color is a difference in the proctective pigment of the skin (melanin). It is our bodies natural way to protect the body in different climates, and weather conditions. Generally people from sunny places (Africa, Cambodia, etc) have darker skin tone. You can see this in the summer... if you are light skinned and you go out for a long period you may get burnt, turning your light skin to red, then the burn eventually becomes tan, the more you are in the sun the tanner you are.

Now that is the easily explanation...

The more complex one is that Melanin comes in two types, red (pheomelanin) and dark brown to black (eumelanin). The amount and type of melanin a person has is determined by 4-6 genes. One copy of the genes is inherited from the father, one copy from the mother. Each gene comes in several different DNA codes which, depending on which genes you inherit, resulting in different skin tone.

We know that skin color is governed by more than one pair of genes. For simplicity, let's assume there are only two, 1 located at positions A and B on the chromosomes. One form of the gene, "M," "says" to make lots of melanin; another form of the gene, 2 "m," says to only make a little melanin. At position A we could have a pair such as MAMA, MAmA, or mAmA 3 which would instruct the skin cells to make a lot, some, or little melanin. Similarly, at position B we could have the gene pairs MBMB, MBmB, or mBmB instructing cells to make a lot, some or little melanin. Thus very dark people could have MAMAMBMB.

For the rest of the article see:
How did different human skin colors come about? - ChristianAnswers.Net

There are genetic charts that explain some of the genetics.

Another good article is in:

Why do people have different colored skin? | Answerbag.com